Capsules made by a complex coacervation process are often supplied in an aqueous slurry. Often, encapsulated materials can diffuse out the capsule shell through the pores of the capsules into the liquid phase due to the concentration gradient. This leakage may result in the loss of the encapsulated materials. In various applications, such as dentifrice compositions, it may be desirable to reduce the rate of leakage of the capsule contents and increase the capsule stability.